The inlet conditions

As part of this study, we therefore imposed the velocity in the inlet that is a function of the Reynolds number and temperature.

The outlet conditions

Here the dynamic pressure is null, which means that the total pressure is equivalent to the atmospheric pressure.

The walls conditions

Defaults these are conditions obtained via an exchange of the boundary conditions at the interface between the two solid-fluid domains of the annular space, between the fluid domain and the domain solid of the external tube which is in the one side a coefficient of heat exchange, and in the other side, a constant temperature imposed to the wall. Adiabatic conditions are placed on the interface between the two solid-fluid domains, between the fluid domain and the solid domain of the inner tube.